On automobiles, recreational vehicles, vans, small trucks, and virtually all other vehicles, a door check for each vehicle door is usually considered a necessity. The door check often provides two open positions; in one the door is partially open and in the other the door is fully open. Even the full open position may be appreciably less than ninety degrees. In some vehicles the door check provides only one open retention position.
Door checks of this sort are quite common and have been used for many years. However, they are far from uniform in construction or in application. In many vehicles the manufacturer provides a check mechanism that is separate from the door hinges. In this arrangement, particularly in small cars, each door is supported upon two simple hinges that do not establish any retained or detented open positions for the door. In other instances, particularly in larger automobiles, the manufacturer may prefer hinges that incorporate door checks in the hinge structures. Thus, in a typical large car construction, each door is hung from two hinges, and one of those hinges includes a door check establishing two retention or detented positions for holding the door open.
Vehicle door checks have exhibited some substantial difficulties. Thus, the door checks used in automobiles and similar applications, whether separate from or combined with hinges, have frequently required lubrication, without which they tend to squeak and to make other undesirable noises. Some of these door checks only produce noises when opened to full detented open position or beyond. Many of these door checks have an inadequate operating life; they do not last for the full life of the vehicle. Corrosion may also be a substantial problem. In at least some door checks, processing of the vehicle body after installation of the doors, particularly in the curing of external finishes, may require temperatures well beyond the tolerance range of materials used in the door check mechanisms. Thus, it is not uncommon for a vehicle body to be subjected, at least for a brief interval, to temperatures up to near 400.degree. F. after the door installations are completed. This may result in appreciable damage to a door check, whether incorporated in or separate from a door hinge, and may even require replacement of the door check.